Styling tweaks for preferences

Styling tweaks for preferences

Make dividers full width, increase size of preference category icons to
recommended minimum size for touchable items.

BUG=414438
Committed: https://crrev.com/4d026c85f12efc21aefd37006b8d37be81c0cffa
Cr-Commit-Position: refs/heads/master@{#310778}

[Theresa, 2015-01-08 22:11:56]

twellington@chromium.org changed reviewers:
+ newt@chromium.org

[newt (away), 2015-01-08 22:18:59]

lgtm. thanks!

[Theresa, 2015-01-08 22:19:55]

The CQ bit was checked by twellington@chromium.org

[commit-bot: I haz the power, 2015-01-08 22:21:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/788053007/20001

[Theresa, 2015-01-08 22:23:14]

The CQ bit was unchecked by twellington@chromium.org

[Theresa, 2015-01-08 23:17:07]

The CQ bit was checked by twellington@chromium.org

[Theresa, 2015-01-08 23:17:19]

The CQ bit was unchecked by twellington@chromium.org

[Theresa, 2015-01-09 01:37:26]

PTAL

I restricted the padding change to L+ devices. On pre-L, the listItemPadding (or
whatever the attributes called) is much smaller than on post-L and it doesn't
look good. I spent a couple of hours trying to massage the pre-L design to look
right, but we have some many custom preferences, etc. it was becoming
increasingly difficult (will send some screenshots to illustrate). I think from
a UX perspective this is fine, because pre-L Google settings don't have
full-width divider lines either.

[Theresa, 2015-01-09 16:00:43]

The CQ bit was checked by twellington@chromium.org

[commit-bot: I haz the power, 2015-01-09 16:01:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/788053007/40001

[commit-bot: I haz the power, 2015-01-09 16:40:55]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-01-09 16:41:36]

Patchset 3 (id:??) landed as
https://crrev.com/4d026c85f12efc21aefd37006b8d37be81c0cffa
Cr-Commit-Position: refs/heads/master@{#310778}